Timberlake broke the news on UK’s Capital FM radio station (originally reported on MTV UK), saying that he and the Mumford & Sons’ namesake “worked on the music together and I don’t know any other world where we would have the opportunity to collaborate like that, but it was so much fun.”

“Inside Llewyn Davis” is loosely based on folk singer Dave Van Ronk’s memoir about the folk scene in Greenwich Village in the 1960s. The film, which screened in Los Angeles right before the Grammys, doesn’t have a release date yet. The movie’s soundtrack reunites the Ethan and Joel Coen with frequent collaborator T Bone Burnett, who, of course, worked on the soundtrack to “O Brother Where Art Thou.”